A variety of injuries and conditions require repair of soft tissue damage, or reattachment of soft tissue to bone and/or surrounding tissue. For example, when otherwise healthy tissue has been torn away from a bone, such as a shoulder rotator cuff tendon being partially or completely torn from a humerus (a rotator cuff tear), surgery is often required to reattach the tissue to the bone, to allow healing and a natural reattachment to occur. A number of devices and methods have been developed for performing these surgical repairs, some of the more successful methods including the use of suture anchors or, generically, “suture fixation members,” which typically include an anchor body having one or more suture attachment feature, and a tissue or bone engaging feature for retaining the suture anchor within or adjacent to the tissue or bone. Depending on the specific injury, one or more suture anchor connected to, or interconnected by, one or more segment of suture, may used to perform the repair.
Surgery can also be required when a tear occurs in the substance of a single type of tissue, for example in the meniscus of the knee (a meniscal tear). One method of repairing such a tear is to stitch it closed by passing a length of suture through the tissue and tying the suture. Suture can also be used in conjunction with one or more suture anchor to repair such tissue tears. Sutures can be fastened to suture anchors and to tissue using knots tied by the surgeon during a repair procedure, or using “knotless” devices and methods, where one or more anchor and one or more suture can be connected and tensioned without the surgeon needing to tie knots during the surgery. Knotless anchoring is of particular utility for minimally invasive surgeries such as endoscopic or arthroscopic repairs, where the surgeon must remotely manipulate the suture at the surgical site using tools inserted through a small diameter cannula or endoscopic tube, which can make the knotting process difficult and tedious.
Various methods are used to provide knotless anchoring, including anchors that automatically lock a suture in position as the anchor is deployed in tissue, anchor components that can controllably lock a suture to the anchor after the anchor is deployed, devices that enable a suture to slide through them in one direction only, and preformed knots that can be tightened by the surgeon using a simple tool, or by tensioning one or more suture strand extending from the knot.
While many suture anchoring systems have been developed for repairing torn tissue, current devices are not without their drawbacks. Some knots or other anchor components may “stand proud” above the repaired tissue's surface especially that surface facing weight bearing contact with bone such as the interface between the femur and the meniscus and interfere with movement and healing of, for example, articulating joint tissue, or the knot's position relative to the anchor or nearby tissue may not be fully under the surgeon's control, in some situations providing a less than optimal repair. In surgeries where two or more suture anchors are joined by suture to repair an injury, any knots or joined suture segments positioned along the suture connecting the anchors to one another can become stress points that limit the ultimate strength of the surgical repair or contribute to surgical trauma.
Accordingly, there remains a need for improved methods and devices for repairing torn or damaged tissue, and in particular for methods and devices suitable for arthroscopic repair of torn or otherwise damaged tissue using suture anchors. There also remains a need for methods and devices that reduce the risk of damage to the tissue being repaired, and that provide a low profile to eliminate interference with movement and healing in articulating joints.